APEX EKG TEST EXAM – 200+ QUESTIONS WITH
CORRECT ANSWERS & RATIONALES
EXAM OVERVIEW
The APEX EKG certification exam tests competency in electrocardiogram
(ECG/EKG) interpretation, cardiac rhythm analysis, and clinical decision-
making. This comprehensive test bank covers foundational EKG concepts,
rhythm identification, lead placement, waveform analysis, and treatment
priorities based on current guidelines.
Key Topics:
• Normal EKG intervals and measurements
• Sinus rhythms (normal, bradycardia, tachycardia)
• Atrial rhythms (A-fib, A-flutter, PAC, MAT)
• Junctional rhythms and rhythms
• Ventricular rhythms (PVC, VTach, VFib, Torsades)
• AV Heart Blocks (1st, 2nd Type I/II, 3rd degree)
• Pacemaker rhythms and troubleshooting
• Electrolyte imbalances on EKG
• 12-lead EKG interpretation (axis, leads, anatomy)
QUESTIONS 1–50
1. What is the normal rate range for a sinus rhythm in a healthy adult?
,A) 40-60 bpm
B) 60-100 bpm
C) 100-120 bpm
D) 120-150 bpm
Correct Answer: B) 60-100 bpm
Rationale: The SA node typically discharges at a rate of 60–100 times per
minute, which generates a normal sinus rhythm. Rates below 60 are
bradycardic; above 100 are tachycardic .
2. Which lead is commonly used as the ground reference in a standard
12-lead EKG?
A) LA (Left Arm)
B) RA (Right Arm)
C) RL (Right Leg)
D) LL (Left Leg)
Correct Answer: C) RL (Right Leg)
Rationale: The right leg electrode serves as the reference point (ground) to
reduce electrical interference (noise) in the EKG signal .
3. How many chest electrodes are typically used in a 12-lead EKG?
A) 4
B) 6
C) 8
D) 10
Correct Answer: B) 6
,Rationale: A standard 12-lead EKG uses 6 chest (precordial) electrodes (V1–
V6) and 4 limb electrodes (RA, LA, RL, LL) for a total of 10 electrodes .
4. What is the normal duration of the PR interval on an EKG?
A) 0.04 – 0.10 seconds
B) 0.12 – 0.20 seconds
C) 0.20 – 0.30 seconds
D) 0.30 – 0.40 seconds
Correct Answer: B) 0.12 – 0.20 seconds
Rationale: The PR interval (normal 0.12–0.20 seconds) reflects the time for
the impulse to travel from the SA node through the atria, AV node, and His-
Purkinje system to begin ventricular depolarization .
5. On EKG paper, a small block (1 mm) at standard speed (25 mm/sec)
represents:
A) 0.04 seconds
B) 0.10 seconds
C) 0.20 seconds
D) 0.40 seconds
Correct Answer: A) 0.04 seconds
Rationale: At 25 mm/s, 1 mm (one small box) = 0.04 seconds, a large box (5
mm) = 0.20 seconds .
, 6. Determine the rate of a regular tracing showing a distance of 4 large
boxes between consecutive R waves.
A) 65 bpm
B) 75 bpm
C) 85 bpm
D) 95 bpm
Correct Answer: B) 75 bpm
Rationale: For regular rhythms, rate = 300 ÷ number of large boxes between
R-R intervals. 300 ÷ 4 = 75 bpm .
7. Which EKG waveform represents ventricular repolarization?
A) P wave
B) QRS complex
C) T wave
D) U wave
Correct Answer: C) T wave
Rationale: The T wave corresponds to repolarization of the ventricles. It
generally follows the QRS and is usually upright in most leads .
8. A normal P wave should measure:
A) >0.12 seconds in duration
B) <0.12 seconds in duration
C) Taller than the R wave in lead I
D) Absent throughout the tracing
CORRECT ANSWERS & RATIONALES
EXAM OVERVIEW
The APEX EKG certification exam tests competency in electrocardiogram
(ECG/EKG) interpretation, cardiac rhythm analysis, and clinical decision-
making. This comprehensive test bank covers foundational EKG concepts,
rhythm identification, lead placement, waveform analysis, and treatment
priorities based on current guidelines.
Key Topics:
• Normal EKG intervals and measurements
• Sinus rhythms (normal, bradycardia, tachycardia)
• Atrial rhythms (A-fib, A-flutter, PAC, MAT)
• Junctional rhythms and rhythms
• Ventricular rhythms (PVC, VTach, VFib, Torsades)
• AV Heart Blocks (1st, 2nd Type I/II, 3rd degree)
• Pacemaker rhythms and troubleshooting
• Electrolyte imbalances on EKG
• 12-lead EKG interpretation (axis, leads, anatomy)
QUESTIONS 1–50
1. What is the normal rate range for a sinus rhythm in a healthy adult?
,A) 40-60 bpm
B) 60-100 bpm
C) 100-120 bpm
D) 120-150 bpm
Correct Answer: B) 60-100 bpm
Rationale: The SA node typically discharges at a rate of 60–100 times per
minute, which generates a normal sinus rhythm. Rates below 60 are
bradycardic; above 100 are tachycardic .
2. Which lead is commonly used as the ground reference in a standard
12-lead EKG?
A) LA (Left Arm)
B) RA (Right Arm)
C) RL (Right Leg)
D) LL (Left Leg)
Correct Answer: C) RL (Right Leg)
Rationale: The right leg electrode serves as the reference point (ground) to
reduce electrical interference (noise) in the EKG signal .
3. How many chest electrodes are typically used in a 12-lead EKG?
A) 4
B) 6
C) 8
D) 10
Correct Answer: B) 6
,Rationale: A standard 12-lead EKG uses 6 chest (precordial) electrodes (V1–
V6) and 4 limb electrodes (RA, LA, RL, LL) for a total of 10 electrodes .
4. What is the normal duration of the PR interval on an EKG?
A) 0.04 – 0.10 seconds
B) 0.12 – 0.20 seconds
C) 0.20 – 0.30 seconds
D) 0.30 – 0.40 seconds
Correct Answer: B) 0.12 – 0.20 seconds
Rationale: The PR interval (normal 0.12–0.20 seconds) reflects the time for
the impulse to travel from the SA node through the atria, AV node, and His-
Purkinje system to begin ventricular depolarization .
5. On EKG paper, a small block (1 mm) at standard speed (25 mm/sec)
represents:
A) 0.04 seconds
B) 0.10 seconds
C) 0.20 seconds
D) 0.40 seconds
Correct Answer: A) 0.04 seconds
Rationale: At 25 mm/s, 1 mm (one small box) = 0.04 seconds, a large box (5
mm) = 0.20 seconds .
, 6. Determine the rate of a regular tracing showing a distance of 4 large
boxes between consecutive R waves.
A) 65 bpm
B) 75 bpm
C) 85 bpm
D) 95 bpm
Correct Answer: B) 75 bpm
Rationale: For regular rhythms, rate = 300 ÷ number of large boxes between
R-R intervals. 300 ÷ 4 = 75 bpm .
7. Which EKG waveform represents ventricular repolarization?
A) P wave
B) QRS complex
C) T wave
D) U wave
Correct Answer: C) T wave
Rationale: The T wave corresponds to repolarization of the ventricles. It
generally follows the QRS and is usually upright in most leads .
8. A normal P wave should measure:
A) >0.12 seconds in duration
B) <0.12 seconds in duration
C) Taller than the R wave in lead I
D) Absent throughout the tracing
